Asphalt additive composition



man

Patented Mar. 3Q, 1954 TENT OFFICE ASPHALT ADDITIVE OOMPOSETION Morris Feller, Chicago, ill.

Laren, Munster, Ind, Company, Chicago, Ill

diana N Drawing.

ass

and Frederick H. Macigncrs to Standard Oil a corporation of In- Application December 21, 1950, Serial No. 202,124

11 Claims. (Cl. 196-243) This invention relates to an improved asphalt additive composition and it pertains more particularly to additive compositions which can be readily incorporated in asphalts, particularly cutback asphalts, and road oils for improving the coating of wet aggregates.

Paving asphalts ordinarily do not coat and adhere well to mineral aggregate unless the aggregate is substantially dry and it has, therefore, been conventional practice to dry the aggregate immediately prior to coating it with asphalt. Furthermore, many asphalts are stripped or displaced from aggregate by the action of water after a pavement has been laid. An object of this invention is to provide an improved asphalt additive which is efiective in small amounts for causing asphalt to adhere to wet aggregate and for preventing the displacement or stripping of asphalt from an asphalt coated aggregate.

Asphalt additives heretofore proposed for enabling the coating of wet aggregate and minimizing the tendency toward stripping of asphalt from aggregate have been deficient in at least one or more respects. Some have been satisfactory on siliceous aggregates but unsatisfactory on calcareous aggregates such as lime stone, or vice versa; an object of this invention is to provide an additive which will be effective for all types of aggregates. Certain prior additives have been effective only in such large concentrations as to be prohibitively expensive; an object of this invention is to provide a low cost additive which is effective in small amounts. Certain prior additives have been found to decompose, settle out or otherwise become ineiiective when stored at high temperatures for a long period of time; an object of this invention is to provide an additive which will not decompose, settle out or be rendered ineffective by prolonged storage at high temperature and which will meet most rigorous hot settling test requirements.

A further object of this invention is to provide an additive which is normally liquid and readily compatible with asphalt so that it may be incorporated in asphalt at ordinary temperatures and with ordinary mixing means. Other objects will be apparent as the detailed description of the invention proceeds.

This invention is based on the discovery that so-called ebony fat has remarkable effective ness in solutizing certain alkaline earth or heavy metal sulfonates, particularly the so-called calcium green acid soaps, in mineral oils and/or asphalts. At the same time, the "ebony fat remarkably enhances or synergiZes the effectiveness of such soaps when applied as an asphalt additive for improving the coating of wet aggregates and the prevention of subsequent water stripping of asphalt from coated aggregates. The solutizing effect may be utilized in the dehydration of the calcium sulionate which is required for asphalt compatibility and it is of great importance in preventing the loss of effectiveness of the additive when asphalt containing such additive is stored for prolonged time at high temperatures. it has been found that when neither an asphalt containing the calcium soap as an additive nor an asphalt containing ebony fat as an additive will meet the strict wet coating test, a

. combination of the ebony fat with the calcium sulionate will not only meet such test, but will also provide a more adherent coating and one less subject to stripping than can be obtained by either additive alone or by other additives known to the art.

The improved additive consists essentially of a mixture of ebony fat and an alkaline earth or heavy metal soap, such as calcium sulfonate, preferably incorporated in a portion of the oil with which the asphalt is normally admixed to form so-called cut-back asphalt. the proportion of ebony fat to calcium sulfonate should be in the range of about 4:1 to 1:4, the preferred ratio being about 1:1. Such additive is incorporated in cut-back asphalt, road oil or the like in amounts in the range of 5% to 10% based on total ebony fat plus calcium sulfonate components in the additive, the preferred amount of additive in most instances being in the range of about 1 to 4%. In other words, the preferred asphalt composition is one in which the asphalt contains about 1% to 2% of calcium sulfonate and an approximately equal amount of ebony fat.

The asphalt may be of any type which is useful for the coating of mineral aggregates or'for the coating of other materials or surfaces where a water resistant bond between the surface and the asphalt is advantageous or necessary. The term asphalt as employed herein is intended to be synonymous with bitumen and to cover a liquid semi-solid or solid plastic bituminous material of he type employed for the making or surfacing of highways and/or pavements, caulking compounds, ceiling compounds, water impervious paints, roofing materials, etc. Such asphalts or bituminous materials are mixtures of hydrocarbons of natural or pyrogenous origin and are usually derived from petroleum or coal but may occur as such in nature. Asphalts may be derived as distillation residues or crackingresldues with or without oxidation or air blowing and with or without addition of other compounding agents or additives. As a specific example of an asphalt employed in our tests, a cracked petro-- leum residuum was cut back with a light aromatic diluent boiling .in the range of 400 to 709 F. to give a cut back product of the following specifications:

Flash Not less than 150 F. Furol viscosity at 140 F. 120-200 seconds Inspection of residue after distilling to 680 F.:

ASTM penetration at 120-300 77 F. ASTM ductility at 77 F. Not less than 100 ASTM ductility at 60 F. Not less than 100 C014 solubility Not less than 99.5%

Ebony fat is a propane-insoluble residue obtained from vegetable and animal fats and oils, illustrative properties of ebony fats from animal fat and vegetable oil, respectively, being Iodine Number The above properties are, of course, merely illustrative, and itshould be understood that both the amount and the properties of the propane insoluble residues depend upon the nature of the crude fatty material which is subjected to the propane fractionation and upon the particular conditions employed. for effecting fractionation. The term crude as used herein means that the color bodies and other materials, insoluble in 6 to 30'volumes of propane at about 140 F. to 190 F., have not been removed regardless of whether or not the fatty material has been destearinized.

.The'method of fractionating the animal, marineand vegetable fatty materials with propane to obtain 'ebony fat is well known to those skilled in the art and one example thereof is commonly referred to as the Solexol process currently in commercial use and described in Industrial and Engineering Chemistry, February 1949,

p. 230. A system for effecting such fractionation is described in considerable detail in U. S. 2,505,338'and 2,521,234. For most crude animal fats, marine oils and vegetableoils and similar fatty: materials including acids split'from such fats, the fractionation conditions are employed which give a propane insoluble residue of about 1%, i.-e. about 0.2 to 2%, althoughin some cases such residue may be as large as 5% or even The word ebony denotes the dark-color and the word fats denotes that the source is from a fatty material, such as a crude animal or vegetable oil, fat or'fatty acid; the exact composition of ebony fat has not been fully determined but it apparently includes color bodies, resins, gums, phosphatides, a certain amount of glyceride and polyglyceride material and some free fatty acid. In some cases, the ebony fat contains water and/or solids; insuch cases, the water may-be removed by heating, stripping with anJnert-gas, and/orair blowing. When abody of ebony fat is allowed to stand for a long period of time and solids settle out to the bottom, the materials above such settled solids are more effective than the settled solids. ince the ebony fat is to be employed in an oil or asphalt composition, the ebony fat may be extracted with an oil solvent which is to form a part of the additive or asphalt composition since it will be noted from the above properties that the material is at least about 99% soluble in benzene; such solution in the solvent provides a simple method of eliminating undesired Water and/ or insoluble solids. The use of ebony fats per se as an asphalt additive is described and claimed in a copending application No. 171,555, filed June 30, 1950.

The calcium sulfonate or equivalent soap is preferably calcium salt of a preferentially water soluble sulfonic acid obtained as by-product in petroleum refining process for the production of white oils. lT'he manufacture of such soaps and their use per se as asphalt additives is described and claimed in copending application Ser. No. 108,428, filed August 3, 1949 which issued as U. S. Patent 2,669,525, February 10, 1954. When a petroleum distillate treated with sulfuric acid of at least about 95% strength in the manufacture of white oils, an acid sludge is separated from the treated oil. This acid sludge is hydrolyzed and settled to permit stratification of weak sulfuric acid which results from the hydrolysis. After withdrawing such weak sulfuric acid, the remaining portion of the acid sludge, commonly referred to as liver, is diluted with at least about three volumes and preferably about five volumes of water. The diluted liver is then heated to a temperature in the range of 90 to 200 F. and the sulfonic acid component (the liver may contain approximately sulfonic acid) is then neutralized with an oxide, hydroxide or carbonate of an alkaline earth metal, such as calcium, strontium, barium, or a heavy poly'valent metal such as lead, iron, zinc, copper, cobalt, manganese, etc, although an alkaline earth metal and particularly calcium is preferred since it has been found to give outstandingly good results. Preferably, the amount of lime, for example, which is added at this stage is not sufficient to completely neutralize all acids. Reaction may be accelerated by intimately mixing the added lime with diluted liver, for example, by air blowing when the reaction is completed, the precipitated calcium sulfonate is allowed to settle, the supernatant liquid is drawn off and a hydrocarbon. diluent, preferably an aromatic hydrocarbon such as a cycle stock produced in thermal or catalytic cracking boiling in the range of 400 to 700 F., is added to the crude sulfonate mixture in amounts of from about 25% to by weight. After the crude sulfonate and hydrocarbon are well mixed, sufficient neutralizing agent, e. g. lime, is added to completely neutralize the residual acidity. The neutralized mixture of sulfonate and hydrocarbons is then dehydrated to lower the water content to an amount less than 10 or 15%, and preferably less than 1% or 2%.

The calcium sulfonate produced in the above manner is not soluble in the aromatic hydrocarbon but appears to be somewhat solutized therein by the water which is present. When the water is removed by the dehydrating step, there is a tendency for the mixture to solidify or to become too viscous to handle. Inorder to keep the soap dispersed in the solvent in fluid form, an alcohol,

such as isopropyl alcohol, may be added in amounts in the range of about 2 to Various alcohols may be used for this purpose, such as butyl alcohol, amyl alcohol, nonyl alcohol, etc. The water removal and/ or alcohol addition should be sufficient to keep the soap in a fluent suspension which is compatible with the asphalt to which it is to be added.

In the preparation of the asphalt additive or this invention, the use of alcohol is not essential since the ebony fat component of the additive may be added prior to the dehydration step and may thus perform its solutizer function in preventing the calcium soap from separating out and preventing the mixture from becoming too viscous when it is cooled to ordinary temperatures. The ebony fat may be added to the diluted calcium sulfonate just prior to the dehydration step or it may be added to the crude calcium sulfonate along with the aromatic hydrocarbon diluent. The lime employed for neutralization may be reacted in part with the ebony fat before its addition to effect neutralization of the sulfonic acid. While these and other operating techniques may be employed, it has been found that highly advantageous results are obtainable by having the ebony fat present in its original or converted state during the dehydration step.

The sulfonic acids produced in the manner hereinabove described are generally referred to in the art as green acids and the soap is called calcium green acid soap. As above indicated, green acid soaps are not oil soluble and although they are somewhat solutized or held in suspension when water or alcohols are present, there is nevertheless a tendency for the soap to settle out, particularly when allowed to stand for a long time at high temperature. The presence of water is objectionable in an asphalt additive from the standpoint of compatibility. It was found that when calcium green acid soap containing a substantial amount of water was dehydrated in the presence of an amount of ebony fat in an amount of about 80 weight per cent of the calcium sulfonate present in the soap and the resulting mixture was stirred while heating to a temperature of 250 F., the water which was driven from the mixture came off smoothly with only a small amount of foaming, which foaming was easily controlled by adjusting the rate of stirring. At 250 F., the mixture was very fluid. As the tem perature dropped to room temperature, the mixture became more viscous and although it could be readily poured at temperatures of the order of 100 to 120 F., it would not flow readily at 80 F. In another run using an amount of ebony fat equal to the amount of calcium sulfonate present in the wet green acid soap, the final dehydrated soap was less viscous and could be poured at room temperature. At no time during either of the above runs was there any indication of phase separation or any tendency to solidify due to the removal of water. The ebony fat was thus very efficient as a dehydrating adjunct and plasticizing agent or solutizer. Furthermore, the soaps thus dehydrated by heating to a temperature as high as 280 F. and until there was no further evolution of steam bubbles, were apparently soluble (i. e. uniformly dispersed with no tendency to settle out), not only in cycle stock but even in naphtha. The final dehydrated soaps contained less than 2% water, the amounts of water being as low as .2 and they had viscosity and handling characteristics similar to ordinary cut back as- 6 phalts. The resulting asphalt additives were fluid and readily compatible with asphalt.

The asphalt additive, which in this particular example consisted essentially of about 25 weight per cent calcium sulfonate (green acid soap), 25 weight per cent of ebony fat and the balance chiefly aromatic hydrocarbon diluent boiling in the range of 400 to 700 F. (with less than 2% of water), was added to the cut-back asphalt hereinabove described to give about 1% by weight of calcium sulfonate and ebony fat, respectively, based on the asphalt. The additive-containing asphalt was found to have excellent wet aggregate coating properties to be very resistant to water stripping. The particular test for determining the aggregate coating properties is performed by placing 20 grams of Ottawa sand in a 2 ounce jar, covering it with one-half inch of water, adding one gram of the asphalt sample, shaking for 30 seconds and observing the extent to which the sand is coated by the asphalt. To pass this test, 160% of the sand must be asphalt coated. The asphalt containing 1% of ebony fat and calcium sulfonate as hereinabove described meets such a test. The same asphalt with 2% of the calcium sulfonate component fails to meet such test and the asphalt containing 2 of ebony fat fails to meet such test. Thus it appears that the ebony fat has a synergistic efiect which is greater than a simple additive effect and it re-' sults in an asphalt of outstanding wet aggregate coating properties.

Another outstanding advantage of the ebony fat-calcium sulfonate additive is its ability to meet hot settling tests. The hot settling test is performed by holding a sample of an asphalt with its contained additive for hours at a temperature of 149 F. and then performing an aggregate coating test on a decanted upper portion of the test material. The dual additive of this invention does not decompose or settle out in such hot settling test so that the decanted upper portion of the asphalt passes a wet aggregate coating test just as readily as the asphalt which has not been subjected to hot settling.

It should be understood that the above examples are given by way of illustration and not by way of limitation and that many modifications and alternative methods of preparation will be apparent to those skilled in the art from the above description. The term ebony fat as employed in the following claims should be undenstood to mean such ebony fat in its combined or uncombined state since at least a portion of it may be neutralized or reacted with lime during its course of preparation.

We claim:

1. A composition of matter useful as an asphalt additive which comprises a mixture of a polyvalent metal green acid soap and ebony fat in a proportion in the range of 1:4 to 4:1, which ebony fat is the propane-insoluble residue obtained in the solvent extraction of a crude fatty material selected from the class consisting of a crude animal oil, fat, and fatty acid, and a crude vegetable oil, fat and fatty acid, with liquefied propane, said insoluble residue being insoluble in 6 to 30 volumes of propane at temperatures of from about F. to about F., and constituting from about fl.2% to about 10% of the crude fatty material from which said insoluble residue is extracted.

2. The composition of claim 1 wherein said mixture is suspended in a hydrocarbon diluent boiling in the range of 400 to 700 F.

3. The composition of claim 1 wherein the polyvalent metal is calcium.

4. A composition of matter comprised essentially of asphalt and containing from about .5 per cent to about per cent of a polyvalent meta-l green acid soap and from about .5 per cent to 5 per cent of ebony fat, which ebony fat is the propane-insoluble residue obtained in the solvent extraction of a crude fatty material selected from the class consisting of a crude animal oil, fat, and fatty acid, and a crude vegetable oil, fat and fatty acid, with liquefied propane, said insoluble residue being insoluble in 6 to 30 volumes of propane at temperatures of from about 149 F. to about 190 and constituting from about 0.2% to about of the crude fatty material from which said insoluble residue is extracted.

5. The composition of claim 4 which also contains an aromatic hydrocarbon diluent boiling in the range of l00 to 700 F.

6. A composition which consists essentially of a major amount of asphalt, a minor amount of an aromatic hydrocarbon diluent boiling in the range f 400 to 700 an amount of calcium green acid soap in the range of .5 to 5 per cent and an amount of ebony fat in the range of .5 to 5 per cent, which ebony fat is the propaneinsoluble residue obtained in the solvent extraction of a crude fatty material selected from the class consisting of a crude animal oil, fat, and fatty acid, and a crude vegetable oil, fat and fatty acid, with liquefied propane, said insoluble residue being insoluble in 6 to 30- volumes of propane at temperatures of from about 140 to about 190 F., and constituting from about 0.2% to about 10% of the crude fatty material from which said insoluble residue is extracted.

7. The composition of claim 6 wherein the proportion of calcium green acid soap to ebony fat is in the range of 1:4 to 4:1.

8. A fluid, asphalt-compatible composition useful as a wet aggregate coating material, which composition is substantially free from insoluble solids, contains not more than about 2% water and comprises essentially calcium green acid soap and ebony fat in a ratio of 4:1 to 1:4 dissolved in an aromatic hydrocarbon diluent having a boiling range chiefly within the limits of 400 to 700 which ebony fat is the propaneinsol uble residue obtained in the solvent extraction of a crude fatty material selected from the class consisting of a crude animal oil, fat, and fatty acid, and a crude vegetable oil, fat and fatty acid, with liquefied propane, said insoluble residue being insoluble in 6 to 30 volumes of propane at temperatures of from about 140 F. to about 190 F., and constituting from about 0.2% to 8 about 10 of the crude fatty material from which said insoluble residue is extracted.

9. The composition of claim 8 in which the amount by weight of calcium green acid soap is approximately equal to the amount by weight of ebony fat and the amount by weight of aromatic hydrocarbon diluent is approximately equal to the combined calcium green acid soap and ebony fat.

10. An asphalt additive which consists essentially of a hydrocarbon diluent boiling in the range of scar F. to 700 F., a polyvalent metal green acid soap, ebony fat, and less than about 2% water, the proportion of polyvalent green acid soap to ebony fat being in the range of 4:1 to 1:4, which ebony fat is the propaneinsoluble residue obtained in the solvent extraction of a crude fatty material selected from the class consisting of a crude animal oil, fat, and fatty acid, and a crude vegetable oil, fat and fatty acid, with liquefied propane, said insoluble residue being insoluble in 6 to 30 volumes of propane at temperatures of from about F. to about F., and constituting from about 0.2% to about 10% of the crude fatty material from which said insoluble residue is extracted.

11. A composition which comprises essentially a major amount of asphalt, a minor amount of an aromatic hydrocarbon diluent boiling in the range of 400 to 700 E, from about 0.5% to 5% of calcium green acid soap, less than 2% water, and from about 5% to 5% ebony fat, which ebony fat is the propane-insoluble residue obtained in the solvent extraction of a crude fatty material selected from the class consisting of a crude animal oil, fat, and fatty acid, and a crude vegetable oil, fat and fatty acid, with liquefied propane, said insoluble residue being insoluble in G to 30 volumes of propane at temperatures of from about 140 F. to about 190 F., and constituting from about 0.2% to about 10% of the crude fatty material from which said insoluble residue is extracted.

MORRIS FELLER.

FREDERICK H. MACLAREN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,905,376 Fischer Apr. 25, 1933 2,329,889 Ewing Sept. 21, 1943 2,339,853 Hemmer Jan. 25, 1944 2,383,097 Weetman Aug. 21, 1945 FQREIGN PATENTS Number Country Date 151,666 Great Britain Oct. '7, 1920 

1. A COMPOSITION OF MATTER USEFULL AS AN ASPHALT ADDITIVE WHICH COMPRISES A MIXTURE OF A POLYVALENT METAL GREEN ACID SOAP AND "EBONY FAT" IN A PROPORTION IN THE RANGE OF 1:4 TO 4:1, WHICH "EBONY FAT" IS THE PROPANE-INSOLUBLE RESIDUE OBTAINED IN THE SOLVENT EXTRACTION OF A CRUDE FATTY MATERIAL SELECTED FROM THE CLASS CONSISTING OF A CRUDE ANIMAL OIL, FAT, AND FATTY ACID, AND A CRUDE VEGETABLE OIL, FAT AND FATTY ACID, WITH LIQUEFIED PROPANE, SAID INSOLUBLE RESIDUE BEING INSOLUBLE IN 6 TO 30 VOLUMES OF PROPANE AT TEMPERATURES OF FROM ABOUT 140* F. TO ABOUT 190* F., AND CONSTITUTING FROM ABOUT 0.2% TO ABOUT 10% OF THE CRUDE FATTY MATERIAL FROM WHICH SAID INSOLUBLE RESIDUE IS EXTRACTED. 